The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Image guided medical and surgical procedures utilize patient images obtained prior to or during a medical procedure to guide a physician performing the procedure. Such procedures can be referred to as computer assisted procedures. Recent advances in imaging technology, especially in imaging technologies that produce highly-detailed, two, three, and four dimensional images, such as computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopic imaging (such as with a C-arm device), positron emission tomography (PET), and ultrasound imaging (US) has increased the interest in image guided medical procedures.
Typical image guided navigation systems require a dynamic reference frame to track the position of the patient when patient movement occurs during the assisted procedure. The dynamic reference frame is generally affixed to the patient in a generally permanent or immovable fashion. The dynamic reference frame may also be used as a fiducial marker and may, therefore, be attached to the patient during the acquisition of pre-operative images. This enables the image space to be aligned with patient space during the navigated procedure.
Various instruments that are desired to be tracked may be used during an operative procedure. Image data is generally acquired, either intra-operatively or pre-operatively, and the instrument is generally illustrated, and superimposed on the captured image data to identify the position of the instrument relative to the patient space. Therefore, the instrument may include tracking sensors, such as electromagnetic coils or optical detection points, such as light emitting diodes or reflectors that may be detected by a suitable tracking system. Also, the dynamic reference frame (DRF) can be used by the tracking system to maintain a registration or localization of the patient space to the image space. The DRF can also include any appropriate tracking sensor that is fixed to a portion of the patient that allows the system to determine whether the patient has moved relative to the image space.
Other types of navigation systems operate as an image-less system, where an image of the body is not captured by an imaging device prior to the medical procedure, such as the device disclosed in U.S. patent application Ser. No. 10/687,539, entitled Method and Apparatus for Surgical Navigation of a Multiple Piece Construct For Implantation, filed Oct. 16, 2003, which is hereby incorporated by reference as if fully set forth herein. With this type of procedure, the system may use a probe to contact certain landmarks in the body, such as landmarks on bone, where the system generates either a two-dimensional or a three-dimensional model of the area of interest based upon these contacts. This way, when the surgical instrument or other object is tracked relative to this area, they can be superimposed on this model.
During surgical navigation, image data of the patient can be correlated with the architecture of various surgical instruments. Typically, each instrument is registered with the surgical navigation system so that when the surgical navigation system detects the instrument, the registration and the architecture of the instrument are matched. During a procedure, however, the medical professional may need to change the orientation of the instrument, his or her orientation relative to the instrument and/or add or remove components to/from the instrument during the procedure. Typically, each of the above changes to the instrument requires an additional registration so that the new instrument configuration is registered with the surgical navigation system.
For example, certain instruments can receive additional components during a medical procedure. The instrument can have a first configuration that defines a bare instrument, i.e., no additional components attached to the instrument. The first configuration can be stored in the surgical navigation system. A component can be added to the instrument, which requires a re-registration so the architecture of the component in addition to the architecture of the instrument is registered with the surgical navigation system. It will be appreciated that as each configuration of the instrument changes, the instrument's new configuration must be re-registered. While the above devices and methods remain useful for their intended purpose there remains room in the art for improvement.